Absolutely, the Rooneys will consider LOTS of things.
The bottom line is, whether you like Tomlin or not, speaking from a statistical perspective he has a very impressive record, and that fact is not likely to be lost on the Rooneys. I'm not making any judgments about whether he took over a Super Bowl team and is running it into the ground, just like I'm not making any judgments about how Noll took over a terrible team and built it into a dynasty - I'm only trying to make a point about statistical performance. There are numerous other factors that go into both of those things, such as the fact that Noll had the benefit of some very high draft picks to help him build that team, while Tomlin has had the mixed blessing of running a team with a record that typically puts it in the bottom half of the draft order, quite often very near the bottom. We all know there's a huge gap in talent between the first 10 picks (most of whom are immediate starters) and the last 10 picks in the first round (many of whom are busts). The down side of being a winning team in the age of NFL parity is that sustaining that performance over many seasons through the draft is harder to do when you are not a big player in free agency. The Rooneys made that bed and have to sleep in it, and I'm sure they're aware of that, and it will factor into their considerations as well.
I think in all of this discussion, people want to take their opinion (that Tomlin is a bad coach, which I agree with), and say that it is a "trend" without substantiating that claim with objective evidence. For instance, a lot of people feel like Tomlin is terrible at using challenges, but he's better than 50% (26-23) over his career (in fact, coming into this season, he LED all active coaches in success rate -
http://misterelevant.com/2014/08/12/the-coaching-challenge-challenge-flag-success-rates/). According to PFR, Belicheat is 39-58. John Harbaugh is 31-38. Jim Harbaugh is 12-22. But don't let facts cloud anyone's judgment that he's terrible at challenges.
And I'll ask you the same question I asked before... with two consecutive 8-8 seasons, if we go 9-7 this year, is that "trending down" or "trending up?" How are you defining "trend?" I realize that the Rooneys want their team to be winners, and win championships, but I would guess that they are mainly motivated by profits, and as long as people don't stop buying tickets and merchandise, they don't see the same "trend" as you and I. Tomlin's record is not a direct reflection of his coaching ability, but the same problems that the team is having (poor drafting, strings of mediocre seasons without playoff appearances) have been ridden out by Noll and Cowher as well, because the Rooneys are not known to panic and make drastic changes.
None of this is a defense of Tomlin's coaching ability, which I've always felt is suspect at best. But I don't see how the Rooneys will break character and fire him despite the fact that, although the team has missed the playoffs the last several years, he still hasn't had a losing record. With parity, injuries and a host of other factors both in and out of the control of the coach, I see plenty that causes me as a fan to say "He's a bum, fire his ***." But I can also step back and look at it dispassionately, and recognize that, all things considered, there isn't a strong enough pattern of poor performance to suggest that the Rooneys will do anything other than stay the course. They didn't panic when Cowher put up a 6-10 season. They didn't blink when Noll went four years without a playoff appearance in the 80s. Tomlin, against all our hopes and dreams, will weather this storm and will coach the Steelers until he decides to retire, or until this team strings together some truly abysmal seasons in a row, not just some 8-8 or 9-7 seasons. That's the pinnacle of Steeler privilege - with the franchise's history of championships, we look at an 8-8 season as unmitigated disaster, while lots of other teams would love to do even that well on a regular basis. So I think, all things considered, no matter what my personal feelings are about Tomlin, it's way premature to say that his performance has worn out his welcome with the ownership.